Traditional cancer treatment strategies include chemotherapy, external beam radiation and surgical excision. Chemotherapy is nonspecific and targets all rapidly dividing cells, resulting in undesirable side effects. In addition, tumors can become resistant to chemotherapy. External beam radiation and surgery are only able to target known tumor sites, and will miss undetectable metastases. In the past decade, the development of targeted antibody therapeutics has demonstrated significant improvements in cancer treatment, increasing the number of patient responses to treatment for several types of cancer (Hudson and Souriau, Nat. Med. 9:129-134, 2003; Nayeem and Khan, Curr. Protein Pept. Sci. 7:165-170, 2006; Tassev and Cheung, Expert Opin. Biol. Ther. 9:341-353, 2009; and Weiner et al., Lancet 373:1033-1040, 2009).